Many software applications allow for some modification in the form of add-on components. Add-on components may enhance a software application and typically may provide increased specialization or customization for a particular use. For example, an application may provide financial analysis for general businesses. An add-on program may provide specialized analysis features that are directed toward a niche business with specialized requirements. Another example may be an application that provides a general user interface to network management. Add-on programs may provide specific management tools for specific services within the interface.
Installation of add-on features typically have multiple operations, including copying files to specific locations, changing registry values, updating configuration files, or operations. Installation in this manner can be made atomic, but an intentional or unintentional change to any of the components may render the application or add-on program unusable.